Page 22 - Dedola2011

the other hand, cluster C (the 8A8 group) showed a spatial positive autocorrelation for
distances up to 40 km (Fig. 4d).

Mitochondrial DNA
8equences of 581 bp (COI), 365 bp (128), and 488 bp (168) were obtained. The most
common COI haplotype was shared by 165 ofthe 174 individuals (about 95%), the
remaining nine distributed as follow: ALB 3 and CHA 5; CDN 2; CHA 2; PAR l; PAR
2; MVE 6; ARG 7; LIT 3. Compared to the results ofEspinosa and Ozawa (2006), only
three new COI haplotypes were found, (Fig. 5).
The three nucleotide substitutions observed in our COI dataset (110 sequences) (Fig. 5)
produced the following two amino acid changes: one in the individuai ARG 7 (8ER-
ASN) and one in CDN 2 (ALA-THR) (see also Espinosa and Ozawa 2006). For 12S,
only two haplotypes (cf. previous sequences from GenBank: Accession Nos. FJ767829
and FJ767830) were detected, the less common ofwhich was found in three individuals
(ARG 9, CGR l, ACS 7). The unique nucleotide substitution observed produced no
amino acid change. For 168, only one hapiotype (cf. previous sequences from
GenBank: Accession Nos. FJ767822). was found. Therefore, no further analysis on the
12S and 16S genes was performed. Considering together the 12S, 16S and COI genes
we found a 92% of mitochondrial haplotypes homology in P. ferruginea.

The following estimates of COI genetic variability were Iow: the number of
hapiotypes h= 9, the number of poiymorphic sites S = 8, the nucleotide diversity n=
0.00018 (± 0.00006), and the haplotype diversity H= 0.101 (± 0.032). The network
(Fig. 5) based on COI sequences has a star-Iike configuration with a very common
centrai haplotype that was spread across alllocations. The eight additionai haplotypes
were directiy connected to the centrai one by oniy one mutation. Both Tajima's (D=-

22

Gìan Luca Dedola: ANALISI DELLA VARIABILITÀ GENETICA DI PATELLA FéRRUGINEA, PATEL-LA ULl'SSIPONENSIS (MOLLUSCA: GASTROPODA) E PINNA
NOBILIS (MOLLUSCA: BIVALVIA): lLCONTRJBUTO DEl DATI MOLECOLARI ALLA CONSERVAZIONE DI SPECIE MINACCIATE - Tesi di douorato in Scienze
della natura e delle sue risorse • indiri7.zo BK>logi.a Ambientale, Università degli Studi di Sassarl